Introduction

Secure Shell (SSH) is a UNIX-based command interface and protocol for securely getting access to a remote computer. SSH is actually a suite of three utilities - slogin, ssh, and scp - that are secure versions of the earlier UNIX utilities, rlogin, rsh, and rcp. SSH commands are encrypted and secure in several ways. Both ends of the client/server connection are authenticated using a digital certificate, and passwords are protected by being encrypted.

SSH for root user

For high-level configuration tasks and server administration, you can enable the root user for your server. This user can modify absolutely everything, so make sure you use it wisely. See Enable root access for instructions.

SSH using sudo

For high-level tasks coupled with increased security, you can set up a sudo user instead. This user normally functions as a lower-level user, but can perform the same tasks as root when necessary. See How do I disable SSH access for the root user? for more information.

For all examples that pertain to the root user, a sudo user can do the exact same thing by adding sudo in front of the rest of the command. You will be prompted for the root password, and then the command will execute.

Example root command:

top

Same command for a sudo user:

sudo top

Connect to the server

You will first need to choose an SSH client.

Mac OS X includes the SSH client Terminal by default.

Windows-based Operating Systems do not come with an SSH client by default. We recommend PuTTY. For information, please see: Using SSH in PuTTY (Windows).

Linux distributions include support for SSH by default as well. Simply start up a terminal.

Login credentials

You should use the following information to log into the server via SSH (replace 00000 with your site number):

Server: s00000.gridserver.com

Username: example.com

Password: This is the same as your Server Administrator FTP password. Read this article if you need to reset this password.

You should use the following information to log into the server via SSH (replace example.com with a domain name that resolves to your server):

Server: example.com or your IP address

Username: This depends on which user you chose to enable. The root username is just root. Your domain FTP user or a different sudo user will have a custom name depending on what you typed when you created the user.

Password: This depends on which user you chose to enable. The root and sudo articles above show how to set a password for those users. The domain FTP user will have the same password that you use for FTP.

If you are new to command-line interfaces, you may want to familiarize yourself with some of the commands first.

It is standard to hit "Enter" after each command, to execute it after you finish typing.

If this is your first time connecting to the server from this computer, you will see the following output. Accept the connection by typing "yes."

The authenticity of host 'example.com (12.33.45.678)' can't be established.
RSA key fingerprint is 3c:6d:5c:99:5d:b5:c6:25:5a:d3:78:8e:d2:f5:7a:01.
Are you sure you want to continue connecting (yes/no)?
yes

You will now be prompted to enter your password. Please note that you will NOT see your cursor moving, or any characters typed (such as ******), when typing your password. This is a standard Terminal security feature. Hit enter.

You are now logged into your Grid via SSH. You should see output like this:

The programs included with the Debian GNU/Linux system are free software;
the exact distribution terms for each program are described in the
individual files in /usr/share/doc/*/copyright.
Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
permitted by applicable law.
example.com@n11:~$

You can begin typing commands at the prompt.

You are now logged into your server via SSH. You should see output like this:

The programs included with the Debian GNU/Linux system are free software;
the exact distribution terms for each program are described in the
individual files in /usr/share/doc/*/copyright.
Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
permitted by applicable law.
root@XX:~$